CD274 and hepatocellular carcinoma: By contrast, the immune cell (IC) score, used in several atezolizumab-based HCC studies, quantifies PD-L1 expression as the proportion of the tumor area occupied by PD-L1–positive tumor-infiltrating immune cells, and PD-L1 “positivity” has been explored at different IC or combined tumor-cell/immune-cell (TC/IC) cutoffs (e.g., ≥1%, ≥5% or ≥10%) [115].